The short answer
Glycyrrhizin-containing licorice can add to potassium-loss concerns during metolazone treatment. Regulatory guidance advises against co-use; ask your prescriber about an alternative.
What this answer covers
Glycyrrhizin-containing oral licorice preparations with oral metolazone tablets. Defined root/stolon preparations are not every processed rhizome, formula or deglycyrrhizinated product.
- Supplement or preparation
- Radix et Rhizoma Glycyrrhizae
- Medication ingredient
- metolazone
Why potassium can be affected
Metolazone can increase potassium loss. The final licorice assessment describes mineralocorticoid effects that can also lower potassium and advises against combining licorice with diuretics. This supports a conditional precaution, without a measured risk percentage for your exact product.
Check the licorice ingredient
The relevant evidence concerns glycyrrhizin-containing preparations from specified Glycyrrhiza species. Plant part, processing and dose matter, and multi-herb formulas can introduce additional exposures. A product called deglycyrrhizinated licorice is not the same preparation; ask the pharmacist to check the full label.
Spacing is not an established solution
Potassium loss is a systemic effect rather than simply a same-time stomach interaction. A few hours between the herb and diuretic has not been shown to prevent it. Ask the clinician how to manage existing co-use and whether electrolyte checks are needed before changing prescribed replacement.
Report symptoms and changes
Report persistent dizziness, cramps, weakness, palpitations or a major change in swelling or urine output. Illness, dehydration and other medicines can contribute. Severe weakness, fainting or a new irregular heartbeat need prompt assessment. Do not treat symptoms by adding salts or increasing the diuretic yourself.
Evidence and practical considerations
Side effects & toxicity
Glycyrrhizin-containing licorice warrants avoidance or clinician-directed review with metolazone because both can contribute to potassium loss.
- Exact scope
- Glycyrrhizin-containing oral licorice preparations with oral metolazone tablets. Defined root/stolon preparations are not every processed rhizome, formula or deglycyrrhizinated product. with Exact metolazone RxCUI6916 IN, confirmed by current RxNorm. Exact metolazone oral tablets in conventional2.5/5/10mg formulation; rapidly absorbed formulations are not assumed interchangeable.
- Medication form and route
- Oral
What remains uncertain
- Exact diuretic potassium warning plus explicit licorice class precaution; no exact botanical dose threshold, event rate or protective gap.
Factors that may matter: Exact preparation and dose; Kidney function; Baseline electrolyte status; Other medicines.
Read the supporting source summaries
Source 1: Current prescribing information
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Patients prescribed oral metolazone tablets.
Recommends electrolyte monitoring and correction if indicated; potassium loss is dose-related. Hyponatremia can be severe. Infrequent hypercalcemia especially with high vitaminD doses or high bone turnover.
How this applies: Exact medication label. Exact metolazone RxCUI6916 IN, confirmed by current RxNorm. Exact metolazone oral tablets in conventional2.5/5/10mg formulation; rapidly absorbed formulations are not assumed interchangeable.
No universal potassium/salt supplementation or fixed vitaminD gap. Other botanicals and diuretics are not automatic exact-pair evidence.
Source 2: Final regulatory assessment
ema.europa.eu · Source check Sep 10, 2026
Population: Users of specified glycyrrhizin-containing licorice root/stolon preparations.
Mineralocorticoid effects can cause hypokalemia, fluid retention and hypertension. Co-use with diuretics or cardiac glycosides is not recommended.
How this applies: Constituent/preparation bridge to the current botanical entry; explicit medication-class precaution.
Defined root/stolon preparations, not every processed Gan cao rhizome/formula. Deglycyrrhizinated preparations differ; no exact combination incidence.
Source 3: Medication terminology
rxnav.nlm.nih.gov · Source check Sep 10, 2026
Population: Terminology.
metolazone is IN.
How this applies: Exact ingredient.
Not clinical evidence.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Sources checked and article drafted. | |
| Research summary published |
Article revision: b18be61a99d89b8a
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.